Self Analysis / Progress

In the past, I've struggled with cellular respiration. This unit, working on botany and photosynthesis really helped me understand the process of cell respiration.

Cell respiration takes place inside the mitochondria of the cell. It is the process of which an organism takes in organic compounds with the presence of oxygen is turned into ATP. Aerobic respiration is respiration in the presence of oxygen.

There are three steps in cellular respiration: glycolysis, kreb cycle, and the electron transport chain. Glycolysis takes place outside the mitochondria in the cytoplasm of the cell. In glycolysis, glucose (six-carbon molecule), is broken down into two molecules of pyruvate, each containing a three carbon molecule. Two ATP is generated for every glucose molecule in this process. The chemical NADH is also yielded from this process.

Pyruvate then diffuses into the matrix of the mitochondria, yielding a pyruvate dehydrogenase conplex, which is going to convert the three carbon molecule into acetyl CoA (two carbon molecule), which will go into the kreb cycle. In order to go from a three carbon pyruvate into a two carbon molecule, the third carbon molecule is released in the form of carbon dioxide.



The kreb cycle gives off the two carbons from the acetyl CoA in the form of carbon dioxide as well as two ATP. The kreb cycle adds energy to NADH and FADH2. NADH and FADH2 both have high energy electrons, which they are going to carry into the electron transport chain.

NADH and FADH2 then moves through a series of proteins (electron transport chain). The energy from those proteins are used to pump protons (hydrogen ions) to the outside of the inner membrane into the inner membrane space. In the electron transport chain, NADH and FADH2 pass off their electrons through the proteins in the electron transport chain, pumping two or three hydrogen ion out as it passes through each protein. The inner membrane space is then overwhelmed by the positive charge. ATP synthase then brings the hydrogen ion back in, attaching the hydrogen onto ADP (with phosphate), creating ATP in the process. The electrons are then added to other protons and oxygen (we breathe in) to create the by-product, water. The oxygen that is inhaled will be the last electron acceptor in the matrix. The protons will then flow through a protein, ATP synthase, and combine with the electrons and oxygen, yielding water. This process yields anywhere between 32 to 34 ATP.

In the event of a lack of oxygen, gycolysis will shut down due to the absence of NAD+.  In order to counter this, lactic acid fermentation takes place. This takes place in the muscle. Cells will take glucose in glycolysis, creating two pyruvate molecules, then furthur converting it into lactic acid, which allows it to accept electrons from NADH in order to yield NAD+. This process precipitates two ATP each cycle. The problem with this cycle is that lactate, which is toxic, will build up in the muscles. This requires oxygen to be broken down.

Another solution to the lack of oxygen (in bacteria) is alcoholic fermentation. Instead of breaking down pyruvate into lactate like in lactic acid fermentation, the pyruvate is broken down into ethynol. The second difference between alcoholic fermentation and lactic acid fermentation is that in alcoholic fermentation, carbon dioxide is yielded instead of a three carbon molecule.

Plant Transpiration Online Lab

JOURNAL QUESTIONS

1) Describe the process of transpiration in vascular plants.
  This is the process of which plants lose excess water into the atmosphere through the stomata located on the underside on the plant. leaves. Most of the water absorbed by the plant's root is lost through transpiration. During photosynthesis, stomatas open to allow the intake of carbon dioxide and the release of oxygen. In this process, large amounts of water are lost to the enviornment via transpiration. 

2) Describe any experimental controls used in the Investigation.
  The control of the experiment is the transpiration of the plants under regular conditions and time intervals (same heat, without fan/heater/lamp).

3) What environmental factors that you tested increased the rate of transpiration? Was the rate of transpiration increased for all plants tested?
  The factors that I tested that increased the rate of transpiration were heat, light, and wind. Wind and heat increased the rate of transpiration for all the plants, but the light only increased the rate of transpiration for the arrowhead, coleus, devil's ivy, english ivy, and geranium plants.

4) Did any of the environmental factors (heat, light, or wind) increase the transpiration rate more than the others? Why?

Overall, wind yielded the highest transpiration rate out of all the factors. Different plants transpire at different rates in order to be well-adapted to the different environments they live in. 

 5) Which species of plants that you tested had the highest transpiration rates? Why do you think different species of plants transpire at different rates?
  The rubber plant had the highest rate of transpiration. Different plants transpire at different rates in order to be well-adapted to the different environments they live in. 

6) Suppose you coated the leaves of a plant with petroleum jelly. How would the plant's rate of transpiration be affected?

  Transpiration would be unable to take place because the petroleum jelly covers the stomatas of the leaves, not allowing neither oxygen and water vapor to leave the plants and prevents carbon dioxide from entering the plant. 

7) Of what value to a plant is the ability to lose water through transpiration?

Transpiration allows the plant to regulate homeostasis, humidity in the atmosphere, and moisture in the soil. Water that becomes part of the transpiration process is used as a vehicle to deliver nutrients from the soil into the plant. 

Plant Hormones

AUXIN

Auxin is the plant hormone responsible for stimulating and controlling plant growth. Auxin is made in actively growing tissue including young leaves, fruits, the shoot apex, and the root. In phototropism, the shaded side of the shoot in a plant will contain more auxin, thus compelling the plant to grow away from the shaded side and towards the light. While in a root cell, though the shaded side of the root will contain more auxin, the shaded side will grow less than the lit side and cause the root to grow away from the light. Auxin is also involved in gravitropism. If a shoot is placed horizontally, the bottom side will contain more auxin than the top side, compelling the bottom side to grow more than the top side. This causes the shoot to bend and grow against the force of gravity and in the correct direction. If a root is placed horizontally, the bottom side will contain more auxin than the top side, causing the bottom side to grow less than the top side. This allows the root to bend in the direction of the force of gravity and grow in the correct direction. The growing pattern and the concentrations of auxin in the plant can be described in the five models for auxin transport. On a cellular level, auxin is essential for cell growth, promoting cellular division and cellular expansion. Auxin contributes to cell differentiation and specification. Depending on the type of tissue, auxin may compel axial elongation (shoots), lateral expansion (roots), or isodiametric expansion (fruits). 

http://upload.wikimedia.org/wikipedia/commons/thumb/9/97/Model_for_auxin_transport.png/330px-Model_for_auxin_transport.png

http://www.plant-hormones.info/iaa.gif

http://www.plant-hormones.info/went1.gif

ABSCISIC ACID

Abscisic acid (ABA) is a plant hormone also known as abscisin II and dormin. It functions in many plant development processes. Abscisic acid stimulates the closure of the stomata, inhibits shoot growth, induces seeds to synthesize storage proteins, inhibits the affect of gibberellins on stimulating de novo synthesis of a-amylase, effects induction and maintenance of dormancy,  and induces gene transcription. Abscisic acid is also the plant hormone that responds to weather stresses such as cold and drought. ABA maintains the dormancy in seed germination, ensuring its growth in the most advantageous environment. 

http://www.plant-hormones.info/aba.gif

ETHYLENE

Ethylene is commonly used in the agricultural industry. Commercial fruit farmers control the timing of the fruit ripening with the application of ethylene gas. Horticulturalists inhibit leaf dropping in ornamental plants by removing ethylene from green houses using fans and ventilation. Ethylene is a hormone that stimulates fruit ripening, flower wilting, and leaf fall. Aging tissues and nodes of stems also produce ethylene. The most well-known effect of this hormone is the compulsion of fruit ripening. It stimulates the conversion of starch and acids to sugars. One trick people use to accelerate the ripening of fruit is to seal unripe food in a paper bag and let the gas released by the first fruit to mature trigger the ripening of the remaining fruit. Ethylene also plays a role in fruit abscission and flower fading/dropping. 

http://www.chinadaily.com.cn/lifestyle/2006-06/01/xin_050603011349097195622.jpg

Flower Power

This rose has multiple layers of vibrantly pigmented petals. It also has a pleasant soft sweet scent. The flower grows at the very top of the bush, allowing easy access by insects. At the very center of the flower, it contains multiple stamens (male) with anthers (creates pollen) blanketed in layers of powdery pollen. The stamens surrounds the single pistil (female). This ensures that insects looking for nectar in the rose are covered in pollen and coat the stigma full of pollen.

This flower's five petals create a target at the very center for insects. The color also fade from deep and bold to light and vibrant. This bush is located on ground level, making it more available to smaller organisms.The flower doesn't give off a distinct scent, but it's stark contrast in color with its straight pointed leaves make it stand out to attention. It contains a couple of stamens, surrounding one tall pistil with a sticky stigma (in order to trap pollen.) The insect must reach deep into the flower in order to access the nectar, in turn also knocking the stamens and pistils together, transferring pollen. Once the insect leaves the flower, it will also rub the pollen is covered in on the stigma. 

 This flowering tree has flowers that grow in a bunch with its opening faced down. The flowers of this tree give off a bubble bath scent. It is most likely that small insects pollinate these flowers because of the small size and the positioning of the flowers.  Its soft pink shade makes it aesthetically desirable.

 The stamens and the pistils. 

The tree bark itself is extremely smooth, not made to ward off unwelcomed consumers. It also extends its leaves widely, creating shade.

There were a large number of ants crawling up and down the tree. It is most likely that they are present for the nectar of the small flowers.